Public policies that affect alcohol consumption and related behaviors can influence a range of health and social outcomes. Advances in scientific research on the effects of various alcohol-related policies depend on well-measured indicators of these policies. Research in this important area has been constrained by limitations on the availability and quality of policy information. Initiatives to provide reliable information on public policies relating to alcohol must contend with the extraordinary complexity of alcohol policy in the United States. Laws, regulations, and jurisprudence address myriad aspects of alcoholic beverage production, packaging, transportation, marketing, taxation, sales, and consumption, as well as the financing and delivery of alcohol-related treatment and preventive services. Many of these policies are established by governments at all levels (Federal, State, county, and municipal). The National Institute on Alcohol Abuse and Alcoholism (NIAAA) developed the Alcohol Policy Information System (APIS) to provide authoritative, detailed, and comparable information on alcohol-related public policies in the United States at both the State and Federal levels. The APIS web site (http://alcoholpolicy.niaaa.nih.gov) is an online resource that provides public access to this detailed information on a wide variety of alcohol-related public policies. Intended primarily as a tool for researchers, APIS features compilations and analyses of alcohol-related statutes and regulations. APIS is designed to simplify the process of ascertaining the state of the law for studies of the effects and effectiveness of alcohol-related policies.